Apparatus and method for prosthodontics

Abstract

The invention relates to a dental tray assembly for intraoral imaging of an edentulous dental arch and/or palate. The dental tray assembly includes a base surface and an opposing external surface. An anterior wall is connected to the base surface and extends arcuately either side of a central axis coinciding, in use, with the labial frenulum. A posterior edge connects opposing sides of the anterior wall. The base surface and the anterior wall together define a concave trough for at least partially surrounding an edentulous arch. A spaced-apart array of ultrasound imaging elements is attached to the dental tray within the trough for emitting and receiving ultrasound signals, the received ultrasound signals being representative of the surface topography and/or sub-surface structures of an edentulous dental arch and/or palate to be imaged. Advantageously, by distributing the array of ultrasound imaging elements across the surface area of dental tray the entire edentulous arch and/or palate can be imaged instantaneously. Optionally, received ultrasound signals can be communicated to a remote device, such as a smartphone, running a software App which processes signals to form a virtual digital impression of the dental arches enabling the manufacture of prosthetic dentures having enhanced comfort and stability.

The invention claimed is: 
     
       1. A dental tray assembly for intraoral imaging of an edentulous dental arch and/or palate; the dental tray assembly comprising:
 (i) a base surface for facing, in use, a dental arch within an oral cavity; 
 (ii) an opposing external surface; 
 (iii) an anterior wall connected to said base surface and extending arcuately on either side of a central axis coinciding, in use, with a labial frenulum, wherein the base surface and the anterior wall together define a concave trough for at least partially surrounding, in use, a dental arch within an oral cavity; 
 (iv) a posterior edge connecting opposing sides of the anterior wall and extending, in use, substantially perpendicular to the central axis; and 
 (v) a gel-filled sac is removably placed within the arcuate trough to provide a deformable interface between the dental tray and a patient's edentulous arches and/or palate: 
 
       wherein a spaced-apart array of ultrasound imaging emitters is attached to the dental tray within the trough for emitting and receiving ultrasound signals, the received ultrasound signals being representative of a surface topography and/or sub-surface structures of an edentulous dental arch and/or palate to be imaged. 
     
     
       2. A dental tray assembly according to  claim 1 , wherein the array of ultrasound imaging emitters is spaced apart across an entirety of the base surface and/or the anterior wall. 
     
     
       3. A dental tray assembly according to  claim 1 , in which the gel is a water-based gel. 
     
     
       4. A dental tray assembly according to  claim 1 , in which the gel within the gel-filled sac is a heat-sensitive settable gel for forming an impression of anatomical surface features of the oral cavity including one or more of the group comprising the palate, ridges and sulci. 
     
     
       5. A dental tray assembly according to  claim 1 , in which the gel-filled sac is formed from a synthetic latex material. 
     
     
       6. A dental tray assembly according to  claim 1 , in which the gel-filled sac is dimensioned such that it fills the arcuate trough and extends above a height of the anterior wall. 
     
     
       7. A dental tray assembly according to  claim 1 , in which the gel-filled sac comprises an attached sheath adapted to envelop the dental tray. 
     
     
       8. A dental tray assembly according to  claim 1 , in which the ultrasound imaging emitters are non-piezoelectric. 
     
     
       9. A dental tray assembly according to  claim 8 , in which the ultrasound imaging emitters are printed on a flexible foil which is conformable to a concave internal surface of the dental tray. 
     
     
       10. A dental tray assembly according to  claim 1 , in which a handle portion projects away from the anterior wall and, in use, extends out of the oral cavity. 
     
     
       11. A dental tray assembly according to  claim 10 , in which a camera is located on the handle for detecting, in use, position of reference points on a patient's face relative to a patient's mouth. 
     
     
       12. A dental tray assembly according to  claim 11 , in which the camera is connectable to an external processing device. 
     
     
       13. A dental tray assembly according to  claim 10 , in which the ultrasound imaging emitters are connected to a power source located in the handle portion. 
     
     
       14. A dental tray assembly according to  claim 13 , in which an aperture is formed in the anterior wall to facilitate a physical connection between the power source and the ultrasound imaging emitters. 
     
     
       15. A dental tray assembly according to  claim 13 , in which the external processing device is a mobile or tablet device. 
     
     
       16. A dental tray assembly according to  claim 1 , in which the ultrasound imaging emitters are connectable to an external processing device. 
     
     
       17. A method of imaging edentulous arches and/or palate comprising the steps of:
 (i) providing a dental tray in accordance with  claim 1 ; 
 (ii) locating a gel-filled sac within the arcuate trough of the dental tray to provide a deformable interface between it and a dental arch and/or palate to be imaged; 
 (iii) applying a layer of gel to the exposed surface of the gel-filled sac; 
 (iv) introducing the dental tray into the oral cavity and moving it towards the dental arch and/or palate to be imaged such that the gel-filled sac is gently urged against and conforms to the shape of said dental arch and/or palate; 
 (v) activating the spaced-apart array of ultrasound imaging elements within the trough of the dental tray; and 
 (vi) receiving a primary data set from the ultrasound imaging elements representative of the surface topography and/or sub-surface structures of the dental arch and/or palate to be imaged. 
 
     
     
       18. A method of imaging the edentulous arches and/or palate according to  claim 17 , in which the step of receiving a primary data set from the ultrasound imaging elements includes processing said data; or
 in which the step of processing the primary data set includes storing the processed data set in a memory for future use; or 
 in which the step of processing the primary data set includes providing a display for displaying a synchronous rendered image of a patient's edentulous arches; or 
 in which the step of locating a gel-filled sac within the arcuate trough of the dental tray is preceded by a step of enveloping the dental tray in a protective sheath; or 
 the step of locating a gel-filled sac within the arcuate trough of the dental tray includes enveloping the dental tray in a protective sheath which is formed integrally with the gel-filled sac.